Refrigerating apparatus



March 9, 1937. BICHOWSKY 2,072,977

REFRIGERAT ING APPARATUS Filed Feb. 26, 1932 gipimMwi/A ATTORNEYS Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE,

assignor, by mesne assignments, to General Motors Corporation, a corporation of Delaware Application February 26,- 1932, Serial No. 595,361

1 Claim.

This invention relates to refrigerating apparatus and more particularly to refrigerating systems having a plurality of cooling units of the flooded type connected to a single refrigerant 5 liquefying apparatus.

In apartmenthouses it is often desired to cool a plurality of refrigerator cabinets with a single refrigerant liquefying apparatus. In such a system it is necessary to properly control and dis- 0 tribute the liquefied refrigerant to the cooling units located in the various refrigerator cabinets. One of the simplest ways of distributing this liquid refrigerant is to use an overflow device which limits the amount of liquid refrigerant contained in each cooling unit except the last cooling unit in the series. In this overflow system, the liquid refrigerant is preferably supplied in ample quantities to the first cooling unit of the series, and after filling this first cooling unit to a proper level, the remainder of the liquid refrigerant overflows therefrom, and is conducted to a second cooling unit. Any desired number of cooling units may be used in a series. The liquid refrigerant overflowing from the first cooling unit is conducted to, fills, and overflows from, the succeeding cooling units in the series into the last cooling unit in the series. Such a system, however, does not provide for the control of the amount of liquid refrigerant in the last cooling unit of the series.

Consequently the objects of my invention include the provision of an automatic means for controlling the amount of liquid refrigerant in the cooling units of an overflow controlled multiple unit refrigerating system. More specifically it is an object to provide means operating in response to the quantity of liquid refrigerant in the last unit for controlling the flow of liquid refrigerant to all of the units.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompany ing drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

The figure is a fragmentary sectional view of an apartment house showing my improved overflow type of multiple unit refrigerating system. 7 Referring to the drawing, there is shown for $0 the purpose of illustrating my invention a portion of an apartment house 20 having rooms 29,

22 and 23 therein which are located upon different floors for the purposes of illustration. Within these rooms 2t, 22, and 23, there are provided 55 the refrigerator cabinets 24, 25 and 26 of the household type, one being located within eachof the rooms.

A multiple unit refrigerating system of the gravity overflow type is provided for cooling these refrigerator cabinets. In this system the refrigerant liquefying apparatus, generally designated by the reference character 30, comprises, for example, a compressor 3| for compressing the refrigerant and for forwarding the compressed refrigerant to a condenser 32 where the refrigerant is condensed and collected. in the receiver 33. The compressor 3| is driven by means of an electric motor 34 through suitable pulley and belt means 35. The operation of the electric motor 34 is controlled by the pressure responsive snap-acting switch means 36 which is connected by means of the conduit 31 to the return conduit 38 of the refrigerating system. Thus, the electric motor 34 is controlled in response to the refrigerant pressure upon the low pressure side of the refrigerating system. If desired, othermeans of controlling the operation of the electric motor may be employed.

From the receiver 33 the liquefied refrigerant is conducted through the conduits 39 and 40 to a cooling unit of the flooded type4l located within the uppermost refrigerator cabinet 24. This cooling unit 4| 'is provided with a reservoir 42 of depending ducts 43 for providing effective heat transfer between the'air within the refrigerator cabinet 24 and the liquid refrigerant in the cooling unit 4|.

for'containing liquid refrigerant and a plurality The liquid refrigerant supply con- 4 duit 40 connects to the reservoir 42 of the evapofloat chamber 43 of a cooling unit 49 located within the refrigerator cabinet 26 in the lower room 22. The evaporator 49 is provided with refrigerant ducts 56 which depend from the reservoir or float chamber 46 for providing effective heat transfer between the air in the refrigerator cabinet 26 and the liquid refrigerant within the cooling unit 49.

The cooling units 4|, 46 and 49 absorb heat from the air within their respective refrigerator cabinets 24, 25 and 28. This absorption of heat causes evaporation of some of the liquid refrigerant in these cooling units and this evaporated refrigerant is returned to the compresser through return conduits 52,53, 44 and 38. In connection with this return of the evaporated refrigerant it should be noted that the overflow conduit 44 connects to the reservoir 45 of the evaporator 48 above the level of liquid refrigerant. This enables the evapprated refrigerant to escape upwardly from the reservoir 45 through this overflow conduit 44 into the reservoir 42. The evaporated refrigerant within the reservoir 42 is returned to the compressor through return conduits 52 and 38, while the evaporated refrigerant within the reservoir 48 of-the cooling unit 49 is removed directly therefrom from the return conduits 53 and 38.

According to my invention, I have provided a means for controlling the quantity of liquid refrigerant within the last cooling unit of the series, namely the cooling unit 48. In order to do this, I so control the supply of liquid refrigerant to the uppermost cooling unit 4| so that the liquid refrigerant overflowing from the two upper cooling units will supply just the proper amount of liquid refrigerant to the evaporator 48 to maintain a proper level of liquid ,refrigerant therein. For this purpose I provide a valve means 88 fastened to one end of the reservoir 48. This valve means 88 comprises a valve body 8| having a valve chamber 62 therein provided with a valve 83 which controls the flow of liquid refrigerant from the supply conduit 38 to the valve chamber 82. The valve chamber 62 is in open communication with the supply conduit 48 which is connected to the valve body 8|. The opening and closing of the valve 63 is controlled by a float means comprising a float ball 84 located within the reservoir 48 which is mounted upon one end of a lever arm 88. the opposite end of which engages the valve 83 to control the opening and closing of said valve. Inasmuch as there is a comparatively high pressure within the supply conduit 38, the valve 63 will be held against the end of the float lever 88 by this pressure. The

end of the reservoir 48 adjacent the valve means 68 is sealed by means of a bellows 88 which has reservoir 48.

By this float controlled valve means 88, the supply of liquid refrigerant to the flrst upper cooling unit 4| is so controlled that when the lever of liquid refrigerant within the evaporator 48 is too low, the liquid refrigerant will be allowed to flow through the supply conduits 38 and 48 to the upper cooling unit 4| until a sumcient amount overflows from the upper cooling units 4| and 48 into the cooling unit 48 to bring the liquid level within the reservoir 48 up to the desired limit. Upon reaching the desired limit, the float 84 will be raised to cause the float level 85 to close the valve 83 and to prevent further flow of liquid refrigerant through the supply conduits 38 and 48 until the level of liquid refrigerant thin the evaporator 48 has been reduced. By t s means I have provided an automatic control for controlling the level of the last cooling unit in the series as well as the upper cooling units. The operation of the compressor is always in this system properly controlled by the low pressurecontrol switch 38. It will be understood that by providing automatic means I for controlling the amount of liquid refrigerant within the last cooling unit of the series, I have greatly increased the usefulness of such a refrigerating system.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

,What is claimed is as follows:

Refrigerating apparatus including a plurality I of enclosures forming compartments to be cooled,

each containing a cooling unit adapted to trap ducting the surplus liquid refrigerant from the highest cooling unit to the second highest 'cooling unit and from the second highest cooling unit to the lowermost cooling unit, a refrigerant liquefying means for supplying liquid refrigerant to the highest cooling unit and withdrawing evaporated refrigerant from the cooling units, said overflow conducting means including a portion adapted to conduct evaporated refrigerant from a lower cooling unit to a higher cooling unit and means responsive to the liquid refrigerant in the lowermost cooling unit for controlling the supply of liquid refrigerant to the upper cooling unit.

FRANCIS RUSBEIL BICHOWBKY. 

